Antique Sterling Enamel Norway Guilloche Brooch

This beautiful antique brooch is made of sterling silver. It features vitreous glass (kiln-fired) enamel in translucent sky blue, applied over a basse-taille or guilloche textured surface, and accented with delicate gold swirls.

Measuring 1 5/8" by 11/16", the brooch is in excellent condition. The back has a simple c-clasp and is signed "Made in Norway 925S" along with a maker's mark that I have not yet been able to identify. At first glance, it looks like a dollar symbol, but closer inspection leads me to believe it may actually be overlapping initials for the maker. The piece dates to the turn of the last century, and has its wonderful original patina intact.